Rhodium(iii)-catalyzed synthesis of trisubstituted furans via vinylic C-H bond activation.

We report an Rh(iii)-catalyzed one-pot synthesis of trisubstituted furan derivatives through C-H activation of α,β-unsaturated ketones with acrylates. The control study revealed that the Heck-type product obtained undergoes Paal-Knorr type cyclization in the presence of an Ag salt. Hence, the Ag salt plays a dual role of a halide scavenger and a Lewis acid catalyst for Paal-Knorr type cyclization. The furan product can be transferred into the respective alcohol and acid derivatives which are useful intermediates in synthesizing biologically active molecules.